How to Select the Ideal Power Supply Unit

In our effort to properly assist our customers in selecting a Corsair power supply unit, or PSU, the most frequently asked questions by far deal with how and why to make certain selections. Let’s face it, computer enthusiasts are definitely an educated and inquisitive crowd so the old "because I said so" type answer we got from Dad as a kid just doesn’t cut it. Of course, we’d love to sell everyone on the planet an AX1200i Digital ATX Power Supply, but that’s also not the correct approach.

Using a AXi Series PSU and Corsair Link's "power" tab with different configurations to determine power usage during different tasks

I was curious as to how much power my gaming PC uses with one, two and three graphics cards installed and how that compared to using the integrated graphics of my Intel® Core™ i5 CPU. Corsair Link and my Corsair AX Series Digital ATX PSU helped me determine that! In this blog entry, I show how much power my PC uses with the different configurations.

Right now I have a Core i5-3570K running at 3.4GHz and three Gigabyte GTX670 2GB cards each running at 980MHz.

Currently, I'm just sitting here typing this while listening to music streaming on Pandora. Not a lot going on, so I'm seeing what sums up to a whole lot of nothing going on within Corsair Link. I'm pulling 224.9W from the wall, which is still a lot... but that's primarily because I'm keeping three graphics cards powered even though I'm not using them. Spoiler: We'll see that number lower as I take cards out of the system, even sitting here doing a whole lot of nothing.

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Haswell compatibility with Corsair power supplies

A report recently published over at the VR-Zone discussing the new 4th generation Intel Core processors, code-named "Haswell", and their ability to go into a lower power sleep state than any previous processor has caused some concern about PSU compatability with the new processor.

When an Intel Core (i3, i5, i7) processor is idle, it goes into a sleep state that requires less power than when the CPU is active. Since the motherboard voltage regulation modules that provide power to the CPU gets their power from the power supply's +12V rail, these sleep states can dramatically reduce the load on the power supply's +12V rail.

Using Corsair Link to Monitor a Corsair AX860i Digital ATX PSU's Power Output, Temperature, and Fan Speed

Many Corsair power supplies feature cooling fans with Zero RPM technology. Essentially, while the power supply is at lower loads and producing less heat, the intake fan is stopped, therefore producing zero noise. As the load on the PSU increases, the power supply produces more heat and that heat needs to be evacuated. A thermistor inside the power supply tells the fan to kick on. Once those temperatures drop to a level that is safe for the power supply to operate without active cooling, the fan cuts off and the power supply runs silently once again.

For my demonstration, I will be using an AX Series AX860i Digital ATX PSU and Corsair Link software to demonstrate how the PSU's power output and temperatures increase with load, and how the power supply fan speed increases and decreases with that temperature.

Corsair and Infsite A.G. Dream PC

What components would you use to build your Corsair Dream PC? Corsair's Ronaldo Buassali recently visited Infsite A.G. in Brazil to build a Corsair Dream PC. Check out some photos of this awesome PC.